Chery A18. Manual — part 37

Diameter of 480M piston skirt

(unit: mm)

Diameter of 480E

piston skirt (unit: mm)

Diameter of UAES’s

new two-valve piston

skirt (unit: mm)

1

79.91-79.92

79.915-79.925

79.915-79.925

2

79.92-79.93

79.925-79.935

79.925-79.935

3

79.93-79.94

79.935-79.94

79.935-79.94

Ex-factory

grouping

4

79.94-79.95

79.945-79.955

79.945-79.955

A

80.20-80.21

80.205-80.215

80.205-80.215

B

80.21-80.22

80.215-80.225

80.215-80.225

Ex-factory

repair

C

80.22-80.23

80.225-80.235

80.225-80.235

Standard

79.93-79.955

79.965-79.975

Oversized by 0.29

80.21-80.235

80.245-80.255

Spare

parts

Oversized by 0.5

80.43-80.455

80.465-80.475

80.435-80.455

Measure the diameter of piston pin bore

Diameter of 480M piston pin bore (unit: mm)

Diameter of 480E piston pin bore (unit: mm)

White

20.630-20.633

White

20.630-20.633

Red

20.633-20.636

Red

20.633-20.636

Blue

20.636-20.639

Blue

20.636-20.639

Measure the diameter of the piston pin

Diameter of 480M piston pin bore (unit: mm)

Diameter of 480E piston pin bore (unit: mm)

White

20.622-20.625

White

20.622-20.625

Red

20.625-20.628

Red

20.625-20.628

Blue

20.628-20.631

Blue

20.628-20.631

Measure the end clearance of the piston
ring
First compression ring: 0.30-0.50mm

Second compression ring: 0.30-0.50mm

Oil ring: 0.40-1.40mm

Measure the axial clearance of piston ring in the piston groove

Height of the piston

ring (unit: mm)

Size of piston ring
groove (unit: mm)

Fit clearance

(unit: mm)

First compression ring

1.60

1.6

0.050-0.082

Second compression

ring

2.0

2.0

0.050-0.082

0.61±0.025

Sealing strip of oil ring

Spring of oil ring

2.68±0.05

4.0

0.01-0.23

Cast iron oil ring

4.0

4.0

0.025-0.055

480 UAES’s new two-valve

Height of the piston ring

(unit: mm)

Size of piston ring groove

(unit: mm)

First compression

ring

1.2（-0.03～-0.01）

1.2（0.03～0.05）

Second

compression ring

1.5（-0.03～-0.01）

1.5（0.02～0.04）

0.46±0.02

Sealing strip of

oil ring

Spring of oil ring

2.75±0.05

2.0±0.02

3（0.01～0.03）

Measure the small-end bore diameter of the
connecting rodΦ20.589

Check whether the big-end injection hole of the
connecting rod is blocked, with the outlet
diameter to be Φ1mm.

0
-0.012

0
-0.012

-0.015
-0.025

+0.03
+0.01

+0.03

+0.01

+0.06

+0.04

+0.06

+0.04

Installation

Piston weights and spare piston skirts are not
grouped, but the piston pin holes shall be
grouped. Before assembly, check the piston
crown marks. The marks of the four cylinders
must be same.

Heat the small end of the connecting rod to
230~400℃, apply SAE50 lube or glue type of
graphite oil, then press the piston pin into the
small end bore of the connecting rod and the
piston pin bore. One end of the piston pin can
be 0.7mm（max）higher than the pin boss or
lower than the pin seat, and the other end shall
be in the pin boss.

The forward pointing arrow on the piston
crown and the forward pointing bump on the
external surface of the piston pin seat shall be
in the same direction with the “F” near the big
end on the connecting rod body (For some
blanks forged with the number “480”, the side
with the number shall be upward.

After connecting the piston, piston pin and the
connecting rod together, print or chisel the
cylinder number (size: 3mm) on the top of the
piston, connecting rod body and left of the
connecting rod cap. The printing shall not lead
to the distortion of the junction plane.

When installing the piston ring, the side with
characters shall be upward and the external
slit of the second compression ring shall be
downward. Detailed order is as follows: (1)
install the oil control piston ring; (2) install
the second compression ring and (3) install
the first compression ring. When installing the
ring, the max. expanding must be less than
(size of cylinder bore + 1.65mm) , otherwise
the ring is subject to distortion or broken off.
The opening of the two sealing strips of Steel
belt combination oil control ring shall be
staggered from each other by 120°while the
one of cast iron oil ring shall be stagger from
that of spiral bushing ring by 180°. The
piston shall be able to rotate freely in the ring
groove and no jamming shall exist.

Forward
pointing bump

First compression ring

2

nd

compression ring

Steel belt combination
oil control ring

Cast spiral oil control ring

Only one side

Size of piston ring

INSTALLATION OF THE PISTON AND
CONNECTING ROD ASSEMBLY

Apply some motor oil in the piston, piston ring
and cylinder, with the first and second
compression ring staggered from the opening
of the oil control piston ring by 120°, then
install the piston and connecting rod assembly
into the cylinder. The piston and connecting
rod assembly may be pushed into the cylinder
by a hammer.

Apply some motor oil on the connecting-rod
bearing shell and install the connecting rod cap
and body. The connecting rod cap is fixed by
two elastic dowels.

Tighten the connecting rod bolts to the moment
of 30-36N.m. Before installation, apply some
motor oil on the bolt heads and threads.

The side clearance of the big end of the
connecting rod is 0.0092-0.268mm.

480# piston ring

Paint mark (type)

Paint mark (type)

No paint (Standard)

No paint (Standard)

Purple paint (oversized by 0.29)

Purple paint (oversized by 0.29)

Blue paint (oversized by 0.5)

Blue paint (oversized by 0.5)